Intelligent power distribution system

ABSTRACT

An intelligent power distribution system including one or more intelligent power strips. The power strips can each include an elongated housing that may be adapted for mounting in an equipment rack. The housing can include a first end, a second end and plurality of power outlets mounted thereon. The first end can have a number of apertures that enable power and signal conductors to enter an interior region of the housing. The second end can include a first and a second communication port. The first communication port may be adapted to enable a computer to communicate with the power the strip. The second communication port may be adapted to enable the power the strip to be daisy chained with a second intelligent power strip. The power strip further includes power management circuitry that can power-on and power-off the power outlets in accordance with an operator defined sequence and delays. The power management circuitry can further sense electrical current drawn by the power strip and control operation of the power strip based on the sensed electrical current to minimize branch circuit breaker tripping.

FIELD OF THE INVENTION

The present invention generally relates to an intelligent powerdistribution system and method, and more particularly to an intelligentpower strip and method of distributing power in an electronic system.

BACKGROUND

Many electronic and electrical systems, such as computer and homeentertainment systems, require that electrical power be applied tocomponents of the system according to a particular sequence to avoidcausing undue stress and possible damage to the components. Particularlywith computer systems, there are many situations in which it isadvantageous to delay activation of peripheral devices until after theparent device is powered up and has attained a quiescent state. Atypical situation is that of a personal or business computer systemwhere the activation of peripheral devices including a monitor, diskdrives and printers, are delayed until after the computer itself isfully on-line. Upon activation of the parent device and after the parentdevice reaches a quiescent operating state, power can be applied to theperipheral devices. This sequence of powering up a computer system isespecially helpful in eliminating undesirable transient currents andrandom logic states caused by simultaneous power up of the parent andperipheral devices.

For example, in many computer systems, power is first applied to thecomputer itself before power is applied to the monitor, because thecomputer supplies the monitor with horizontal and verticalsynchronization pulses necessary to prevent the free running of themonitor's horizontal and vertical oscillators. Allowing the oscillatorsto operate in an unsynchronized condition can result in undue stress tothe oscillators and hard failure of the monitor.

Similarly, power is applied to the computer before power is applied tothe printer. Otherwise, the printer can potentially back-feed power orcontrol signals to the computer and cause the computer to fail toinitialize when the computer subsequently receives power. Consequently,the order and timing of the application of power to and removal of powerfrom certain systems needs to be carefully controlled so as to avoiddamaging the system components.

One solution for providing power to systems similar to that describedabove includes employing an operator to manually turn on the components.Specifically, the operator can power on the computer itself and pausemomentarily to allow sufficient time for the computer to reach aquiescent operating state before providing power to the computer'speripheral devices. This method is generally unsatisfactory, because thetime delay interval is difficult to control and duplicate manually, andfurther, because it may be desirable to ensure that the power up andpower down of the system always occur according to a particularsequence.

Another solution is to use time delay relays (“TDRs”) to provide apredetermined, fixed time delay between application of power to onecomponent and the next. This method is also unsatisfactory, as well asbeing very expensive. TDRs are capable only of providing a fixed, or atbest, a narrowly adjustable, time delay. Furthermore, the power up delayis typically equal to the power down delay, a condition which may beundesirable in certain cases. Finally, the time delay provided by theTDRs is typically not easy to adjust by an operator.

Therefore, a need exists for an intelligent power distribution systemthat can provide power up and/or power down sequences and delays forequipment, which overcomes limitations and deficiencies of the priorart.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an intelligent powerdistribution system and method for using the power distribution system.In embodiments of the present invention, the intelligent powerdistribution system can manage power consumption to minimize tripping ofa branch circuit breaker which provides electrical power to the system.

In one aspect of the present invention, a power distribution system caninclude a plurality of intelligent power strips that can be adapted formounting in an equipment rack. The power strips can be individuallymounted and controlled or the power strips can be daisy chained togetherto form a scalable power strip which can be unitarily controlled. Theequipment rack can have a number of slots that may be adapted tosecurely hold a number of pieces of equipment thereon.

Each intelligent power strip can include a housing that has a first endand a second end. A plurality of power outlets can be mounted on anexterior surface of the housing to provide power to the equipment. Anaperture can be formed on the first end of the housing to enable powerand signal conductors to access an interior region of the housing. Afirst communication port and a second communication port can be definedon the second end of the housing. The first communication port caninclude a communication-in circuit that enables bi-directionalcommunication with the power strip and the second communication port caninclude a communication-out circuit that enables the power strip to becoupled to a second power strip.

The intelligent power strip can further include a power managementcircuit which is defined in the interior region of the housing. Thepower management circuit can include a current sensor circuit that maybe adapted to receive alternating current (“AC”) input power over an ACinput power line. The current sensor circuit can be coupled to the poweroutlets as well as to an AC to direct current (“DC”) power supply. TheAC to DC power supply receives and processes AC power from the currentsensor circuit to generate a plurality of DC voltage values.

The micro-controller can be coupled to the power supply and can receiveone or more voltage values from the power supply. The micro-controllermay be further coupled to a relay driver. The relay driver can receivecontrol signals from the mico-controller to control a plurality ofrelays coupled to the relay driver. The relays can be coupled to thepower outlets defined on the housing of the power strip. The relays canbe controlled to a conductive state to power-on the power outlets andthe relays can be controlled to a non-conductive state to power-off thepower outlets.

The power outlets defined on the power strip can include a first groupof power outlets and a second group of power outlets. The first group ofpower outlets can be coupled to the sensor circuit and the second groupof power outlets can be coupled to the sensor circuit via the relays.The second group of power outlets can each include alight-emitting-diode (“LED”) that can be controlled to illuminate toindicate that each power outlet is powered-on.

The power management circuit can further include an input power sourcesensor circuit. The input power source sensor circuit can be coupledintermediate the power supply and the micro-controller. The input powersource sensor circuit can receive DC input power from the power supplythat is hereinafter defined as primary DC input power, which can beprovided to the micro-controller. The input power source sensor circuitcan further receive secondary DC input power from a secondary powersource. The secondary power source can be provided by thecommunication-in circuit and can provide a redundant power source forthe mico-controller. In the event that the primary DC input powerprovided by the power supply fails or is unavailable, the input powersource sensor circuit can provide the secondary DC input power to themicro-controller.

The micro-controller can be further coupled to an under voltage sensor.The under voltage sensor can be adapted to receive a predeterminedvoltage value from the power supply. The under voltage sensor can beresponsive to the predetermined voltage value falling below apredetermined threshold value by providing a reset signal to themicro-controller. The predetermined threshold value can be defined by auser of the intelligent power distribution system.

A non-volatile memory device can also be coupled to micro-controller toenable the micro-controller to store initialization and configurationinformation as well as other operating parameters.

The micro-controller can also be coupled to an audible alarm that canalert an operator that current on the input power line has exceeded apredetermined threshold value. A mute button coupled to themicro-controller can be actuated to silence the audible alarm.

An overload LED, which is coupled to the micro-controller, can becontrolled to illuminate with a predetermined frequency to indicate anoverload status of the input power line.

In another aspect of the present invention, a power distribution methodincludes energizing an input power line to power-up a first group ofpower outlets on a power distribution system; and controlling aplurality of relays to actuate to a conductive state in accordance witha predetermined sequence and predetermined delay to sequentiallypower-on a second group of power outlets defined on the powerdistribution system. Powering-on the second group of power outletsfurther includes illuminating a light-emitting-diode associated witheach power outlet, defined in the second group, to indicate a powered-onstatus of the second group of power outlets.

Initializing the power distribution system can include programming anormal-threshold value into the power distribution system; programing anoverload-threshold value into the power distribution system; programmingan under-voltage threshold value into the power distribution system;programming delays into the power distribution system, the delays can berelated to powering-on and powering-off power outlets defined in thesecond group; and programming the sequence for which power outlets canbe powered-on and powered-off.

The method can further include sensing current on the input power line;providing the sensed current to a micro-controller; and determining ifthe sensed current is below the normal-threshold value. If the sensedcurrent is determined to be below the normal-threshold value then themethod further includes indicating a normal operating status of thepower distribution system.

The method can further include determining if the sensed current isabove the normal-threshold value; and determining if the sensed currentis below the overload-threshold value. If the sensed current isdetermined to be above the normal-threshold value and below theoverload-threshold value, the method further includes indicating a highcurrent status of the power distribution system.

The method can further include determining if the sensed current isabove the overload-threshold value. If the sensed current is determinedto be above the overload-threshold value, the method further includesindicating an alarm status of the power distribution system.

If the sensed current is determined to be above the normal-thresholdvalue and below the overload-threshold value, the method furtherincludes controlling a first group of predetermined relays to actuate toa non-conductive state to power-off a number of associated poweroutlets.

If the sensed current is determined to be above the overload-thresholdvalue, the method further includes controlling a second group ofpredetermined relays to actuate to a non-conductive state to power-off anumber of associated power outlets.

The method can further include controlling the plurality of relays toactuate to a non-conductive state in accordance with a predeterminedsequence to sequentially power-off the second group of power outlets,which are coupled to the relays; and de-energizing the input power linedefined on the power distribution system to power-off the first group ofpower outlets defined on the power distribution system.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects of this invention, the various featuresthereof, as well as the invention itself, can be more fully understoodfrom the following description when read together with the accompanyingdrawings in which:

FIG. 1a is an intelligent power strip in accordance with an embodimentof the present invention;

FIG. 1b is another view of the intelligent power strip shown in FIG. 1;

FIG. 2a is an enlarged view of a portion of the intelligent power stripshown in FIG. 1;

FIG. 2b is an enlarged view of another portion of the intelligent powerstrip shown in FIG. 1;

FIG. 3 is a power distribution system which includes the intelligentpower strip shown in FIG. 1;

FIG. 4 is a schematic block diagram of power management circuitry whichis included in the intelligent power strip shown in FIG. 1; and

FIG. 5 is a flow chart showing a method of using the power strip shownin FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the present invention numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be obvious toone skilled in the art that the present invention may be practicedwithout these specific details. In other instances, well known methods,procedures, components, and circuits have not been described in detailas not to unnecessarily obscure aspects of the present invention.

In accordance with an embodiment of the present invention, anintelligent power strip is set forth that can provide electrical powerand power management to one or more computer systems and their relatedperipheral devices. The power strip includes internal power managementcircuitry and external power outlets. The intelligent power strip canoperate in conjunction with power management procedures, within thescope of the present invention, to provide a power management system forconventional computer systems. The power management system may beimplemented on a general purpose computer system to provide thatcomputer system with automatic and/or user programmable power managementfeatures.

Referring to FIGS. 1a, 1 b, 2 a, 2 b and 3, in one specific embodiment,the intelligent power strip includes an elongated rectangular housing12, which has a first end 14 and a second end 16. The housing 12 canfurther include a plurality of externally accessible AC power outlets18, through which one or more computers 20 and their related peripherals22 receive power. The power outlets 18 can be mounted along alongitudinal length of one face of the housing 12. A number of mountingbrackets 24 can be coupled to the housing 12 to enable the housing to bemounted to an equipment rack 41 as shown in FIG. 3. The first end 14 ofthe housing 12 can include a number of apertures 14 which may be adaptedto permit power and signal conductors to enter an internal region of thehousing 12. The second end 16 of the housing 12 can include a pluralityof externally accessible communication ports 26. In an embodiment, afirst communication ports 26 a is adapted to permit an external controldevice, such as computer system 20, to communicate with the powermanagement circuitry 50 (FIG. 4) defined in the housing 12. A secondcommunication port 26 b, defined on the second end 16 of the housing 12,is adapted to permit the power management circuitry 50 to communicatewith one or more external devices. The external devices may be one ormore intelligent power strips 10, which can be daisy chained together.

In an embodiment, a power distribution system 40 can include a pluralityof power strips 10 which may be individually operated or which may bedaisy chained together as previously described. The power strips can bemounted in the equipment rack 41. The equipment rack 41 can include anumber of slots 42, which are adapted to securely hold a number ofpieces of equipment (not shown) thereon.

Referring further to FIG. 4, the power management circuitry 50, which ispositioned in the interior region of the housing 12 of the power strip10, includes a current sensor circuit 52. The current sensor circuit 52receives AC input power over an AC input power line 54 from an AC powersource 80 through branch circuit breaker 82.

The power outlets 18 defined on the power strip can include a firstgroup of power outlets 18 a and a second group of power outlets 18 b.The first group of power outlets 18 a can be coupled to the currentsensor circuit and can be defined as constant power outlets. The firstgroup of power outlets 18 a can remain energized as long as power isprovided to the power strip 10 by the AC power source 80 over inputpower line 54. Each outlet, defined in the second group of power outlets18 b, can be coupled to the current sensor circuit via an associatedrelay 56. The second group of power outlets 18 b can remain energized aslong as the relay 56 associated with each outlet is actuated to aconductive state.

The current sensor circuit 52 is further coupled to an AC to DC powersupply 58 which can provide a plurality of DC voltage values to powerother components of the power strip 10. The AC to DC power supply 58 canbe coupled to an input power source sensor circuit 60 which is furthercoupled to a micro-controller 62.

The input power source sensor circuit 60 is adapted to receive primaryDC input power over power line 60 a from the AC to DC power supply 58.The input power source sensor circuit 60 is further adapted to receivesecondary DC input power from a secondary source 61. The secondarysource can include a DC power line 60 c provided by the communication-incircuitry 64 a, which will be described in further detail below. In anembodiment, the primary and secondary DC input power can include a24-volt DC input voltage level.

The input power source sensor circuit 60 normally operates from theprimary DC input power, which is provided by the AC to DC power supply58. The input power source sensor circuit 60 further provides theprimary DC input power to the micro-controller 62 over line 62 a.However, in the event of a failure of the AC to DC power supply 58, thesecondary DC input power can be provided by the input power sourcesensor circuit 60 to power the micro-controller 62. In thisconfiguration, the micro-controller 62 can be redundantly powered byeither the primary DC input power or the secondary DC input power viathe input power source sensor circuit 60.

The input power source sensor circuit 60 can further include circuitryto determine if the input power source sensor circuit 60 is providingpower to the micro-controller 62 from the primary or secondary DC inputpower. In the event that the input power source sensor circuit 60determines that it is providing the secondary DC input power to themicro-controller, the input power source sensor circuit 60 cancommunicate with the operator, via the communication-in circuit 64 a, tonotify the operator that the AC to DC supply 58 has failed.

In one embodiment, the micro-controller 62, which is incorporated in thepower management circuitry 50, is a model XA, PXAG49KBA, which can beobtained from Philips, Amsterdam, Netherlands. The micro-controller 62can receive a sense current signal from the current sensor circuit 52over line 62 b, which represents a proportionate level of current thatis drawn by the power strip 10 over the input power line 54.

The micro-controller is further coupled to the communication-in circuit64 a and the communication-out 64 b circuit. The communication-incircuit 64 a and the communication-out circuit 64 b are respectivelycoupled to the first 26 a and second 26 b communication ports, which aredefined on the external region of the second end 16 of the housing 12.In an embodiment, the communication-in circuit 64 a and thecommunication-out circuit 64 b can each include an RS232 communicationdevice. The RS232 communication devices associated with the communicatewith circuit 64 a and the communication-out circuit 64 b can eachbi-directionally communicate with the mico-controller 62 over theirrespective communication lines Tx1, Rx1 and Tx2, Rx2.

The micro-controller 62 is ether coupled to an audible alarm 66 and amute button 68. The audible alarm 66 alerts an operator, via a speaker13 (FIG. 2b) mounted on the housing 12, of electrical current on theinput power line 54 that exceeds a predetermined threshold value. Theoperator can silence the alarm 66 by actuating the mute button 68. Themicro-controller 62 is also coupled to a non-volatile memory 70, such asan electrically-erasable-programmable-read-only-memory (“EEPROM”). Thenon-volatile memory 70 can store configuration information as well aspower management operating instructions.

An under-voltage sensor circuit 72 is coupled to the micro-controller 62and can provide a reset signal to the micro-controller 62 over line 62c. More specifically, the under-voltage sensor circuit 72 is adapted toreceive a 5-volt value from the AC to DC supply 58. The under-voltagesensor circuit 72 compares the 5-volt value to a predetermined thresholdvalue. If the 5-volt value falls below the predetermined threshold valuea reset signal is provided by the under-voltage sensor circuit 72 to themicro-controller 62 over line 62 c.

For example, the predetermined under-voltage threshold value can beprogrammed to 4.6-volts. Thus, if the 5-volt DC voltage provided to theunder-voltage sensor circuit 72 by the power supply 58 falls below theunder-voltage threshold value of 4.6-volt, a reset signal will beprovided to the micro-controller 62 over line 62 c. The reset signal canreset the micro-controller 62 or maintain the micro-controller 62 at anidle state until the AC to DC supply 58 provides the under-voltagesensor circuit 72 with a voltage value that exceeds the threshold valueor which exceeds the threshold value of 4.6-volts in this example.Maintaining the micro-controller in an idle state, when the 5-volt valueprovided by the AC to DC power supply is below the threshold, minimizesthe micro-controller entering a random logic state.

The micro-controller 62 is further coupled to a relay driver circuit 76.The relay driver circuit 76 is coupled to each relay 56 associated witheach of the power outlets 18 b. Additionally, the relay driver circuit76 can provide a control signal to each relay 56, which is associatedwith each power outlet 18 b, to power-on and power-off each power outlet18 b. More precisely, each relay 56 can be individually actuated betweena conductive state and a non-conductive state for controllably providingpower to each power outlet 18 b that is associated with each relay 56.Each power outlet 18 b can include an LED 15 that can be controlled toilluminate to indicate to an operator that a particular power outlet 18b is powered-on.

An over load LED 78 can be coupled to the micro-controller 62. Theover-load LED 78 can be controlled to illuminate or flash at apredetermined frequency to indicate the operating status of theintelligent power strip 10 to an operator. In one example, the overloadLED 78 can be controlled to illuminate a green light when the currentdrawn over input power line 54 is under a predetermined normal-thresholdvalue. The overload LED 78 can also be controlled to illuminate a greenflashing light when the current drawn over input power line 54 is overthe normal-threshold value, but below a predetermined overload-thresholdvalue. The overload LED 78 can be further controlled to illuminate a redlight when the current drawn over input power line 54 has exceeded theoverload-threshold value.

Referring further to FIG. 5, a method of operating the intelligent powerstrip 100 can include an operator powering-on the first group of poweroutlets 18 a by applying AC power to the input power line 54 at step110. Immediately after applying AC power to the AC input power line 54,the first group of power outlets 18 a can be powered-on to energize oneor more computers 20 or peripheral devices 22 coupled therewith. Afterapplying AC power to the power strip 10, the power strip 10 can beinitialized at step 120. In initializing the power strip 10 at step 110,the operator can program the power strip 10 with a number of systemparameters and operating configurations. The system parameters andoperating configurations can include: a normal-threshold value, anoverload-threshold value, an under-voltage threshold value, delaysrelated to powering-on and powering-off the second group power outlets18 b and the sequence for which power outlets 18 b can be powered-on andpowered-off.

After initializing the power strip at step 120, the second group ofpower outlets 18 b can be selectively powered-on at step 130. The secondgroup of power outlets 18 b can be selectively powered-on, at step 130,in accordance with the operator defined sequence and operator defineddelays. Similarly, one or more computers 20 and/or peripheral devices22, which can be coupled to the second group of power outlets 18 b canalso be powered-on in accordance with the sequence and delays.

After the step of powering-on the second group of outlets at step 130,the method of operating the intelligent power strip further includessensing current on the power input line 54, at step 140, with thecurrent sense circuit 52. The current values sensed by the current sensecircuit 52 are provided to the micro-controller 62 to enable themicro-controller 62 to determine if the normal-threshold value or theoverload-threshold value has been exceeded. At step 150, if it isdetermined that the sensed current on the input power line 54 is belowthe normal-threshold value, normal operation can continue at step 160.If the micro-controller 62 determines that the current on input powerline 62 has exceeded the normal-threshold value at step 150, but isstill below the overload-threshold value, as determined at step 170, themicro-controller can provide a control signal over line 76 a to instructthe relay driver 76 to actuate one or more relays. At step 180, therelays 56 can be actuated to a non-conductive state to power-off one ormore associated power outlets 18 b and associated equipment. At step190, the mico-controller can further control the overload LED 78 toflash a green light to indicate the overload status of the power strip10.

At step 170, if it is determined that the sensed current on the inputpower line 54 has exceeded the overload-threshold value, themicro-controller 62 can provide another control signal over line 76 a toinstruct the relay driver 76 to actuate additional relays 56. At step200, the additional relays 56 can be actuated to a non-conductive stateto power-off additional power outlets 18 b as well as associatedconnected loads. In this manner, one or more power outlets 18 b can bepowered-off depending on the current sensed on the input power line 54to minimize branch circuit breaker 82 tripping, which can cause all ofthe power outlets 18 to power-off. At step 210, the micro-controller 62can turn on the alarm 66 to alert an operator of the overload status ofthe power strip 10. At step 220, the micro-controller 62 can furtherilluminate the overload LED 78 to provide a red light to alert anoperator of the overload status of the power strip 10.

At step 160, an operator can elect to power down the power strip 10. Thepower strip 10 can be powered down by selectively powering-off thesecond group of power outlets 18 b, at step 230. The second group ofpower outlets 18 b can be controlled to power-off in accordance with theoperator defined sequence and operator defined delays. Therefore, thesecond group of power outlets 18 b can be sequentially powered-off tosequentially de-energize the one or more computers 20 or peripheraldevices 22 coupled to the second group of power outlets 18 b. At step240, the first group of power outlets 18 a can be powered-offimmediately after removing power from the AC input power line 54, whichconsequently de-energizes the one or more computers 20 or peripheraldevices 22 coupled to the first group of power outlets 18 a.

In an embodiment, the operator can further program additional powerstrip operating parameters such as a maximum current draw on the inputpower line 54. The maximum current draw value is a percentage of thefull load current carrying capacity of power conductors (not shown)defined in the input power line 54. For example, if the input power lineincludes four copper number 10 American Wire Gauge (“AWG”) conductorswith type-THHN insulation, the full load current carrying capacity ofthe conductors will be approximately 30-Amperes. In this example, theoperator can program the maximum current drawn over these conductors tobe 66 percent of their full load current carrying capacity orapproximately 20-Amperes. As a result, when the power strip 10 isinitially energized the second group of power outlets 18 b can besequentially energized, provided the sensed current on input power line54 does not exceed the percentage of the full load current carryingcapacity of the power conductors or 20-Amperes in this example.Programming the maximum current drawn on the input power line 54 canprevent thermal stressing of the conductors and avoid damaging theconductors as well as avoid branch circuit breaker 82 tripping.

In other embodiments of the present invention, the power strip 10 can bemounted horizontally in the equipment rack 41 or alternatively, thepower strip 10 can be flush mounted on an exterior surface of theequipment rack 41 without departing from the spirit and scope of thepresent invention. Although not shown, it can be readily understood bythose skilled in the art that the power outlets 18 and associated powermanagement circuitry 50 included on the power strip 10 can be adaptedfor mounting in a portable housing without departing from the spirit andscope of the present invention. For example, the portable housing caninclude a rectangular, cubical or cylindrically shaped structure thatcan accommodate the power outlets 18 and power management circuitry 50.In this manner, the principles of the present invention, as describedabove, can be incorporated into a power distribution system that iseasily transportable. Having thus described at least one illustrativeembodiment of the invention, various alterations, modifications andimprovements will readily occur to those skilled in the art. Suchalterations, modifications and improvements are intended to be withinthe scope and spirit of the invention. Accordingly, the foregoingdescription is by way of example only and is not intended as limiting.

What is claimed is:
 1. A power strip, comprising: a housing having afirst end and a second end; a first group of power outlets and a secondgroup of power outlets mounted on an exterior surface of the housing; apower management circuit defined on an interior region of the housing,including: a current sensor circuit that is adapted to receive inputpower over an input power line, the current sensor circuit being coupledto a power supply and to the first group of power outlets; amicro-controller coupled to the power supply and to a relay driver, therelay driver receiving control signals from the micro-controller; aninput power source sensor circuit, coupled intermediate the power supplyand the micro-controller, to receive primary input power from the powersupply and secondary input power from a secondary power source, wherebythe input power source sensor circuit provides the primary input powerto the micro-controller and if the primary input power fails, the inputpower source sensor circuit provides the secondary input power to themicro-controller; and a plurality of relays coupled to the relay driverand to the second group of power outlets, wherein the relays receive acontrol signal from the relay driver to actuate the relays to aconductive state to powering-on the power outlets and the relays receiveanother control signal from the relay driver to actuate the relays to anon-conductive state to powering-off the power outlets; and an undervoltage sensor coupled to the micro-controller and adapted to receive apredetermined voltage-value from the power supply and being responsiveto the predetermined voltage-value falling below a predeterminedthreshold value by providing a reset signal to the micro-controller. 2.The power strip of claim 1, wherein the power strip further includes aplurality of communication ports.
 3. The power strip of claim 2, whereinthe communication ports include a first communication port coupled to acommunication-in circuit and a second communication port coupled to acommunication-out circuit, the communication-in circuit and thecommunication-out circuit being further coupled to the micro-controller.4. The power strip of claim 3, wherein the communication-in circuitincludes the secondary power source.
 5. The power strip of claim 4,wherein the micro-controller is further coupled to a non-volatile memorydevice.
 6. The power strip of claim 5, wherein the micro-controller isfurther coupled to an audible alarm that can alert an operator thatcurrent on the input power line has exceeded a predetermined thresholdvalue.
 7. The power strip of claim 6, wherein the micro-controller isfurther coupled to a mute button that is actuated to silence the audiblealarm.
 8. The power strip of claim 7, wherein the micro-controller isfurther coupled to an overload light-emitting-diode which is controlledto illuminate with a predetermined frequency to indicate an overloadstatus of the input power line.
 9. The power strip of claim 8, whereinthe second group of power outlets includes a plurality of light emittingdiodes that can each be controlled to illuminate to indicate that anassociated outlet is powered-on.
 10. A power distribution methodcomprising the steps of: energizing an input power line to power-up afirst group of power outlets on a power distribution system;initializing the power distribution system, initializing including thesteps of: programming a normal-threshold value into the powerdistribution system; programming an overload-threshold value into thepower distribution system; programming an under-voltage threshold valueinto the power distribution system; and controlling a plurality ofrelays to actuate to a conductive state in accordance with apredetermined sequence and a predetermined delay to sequentiallypower-on a second group of power outlets on the power distributionsystem.
 11. The power distribution method of claim 10, whereininitializing further includes the steps of: programming delays into thepower distribution system, the delays being related to powering-on andpowering-off the second group of power outlets; and programming thesequence for which the second group of power outlets is powered-on andpowered-off.
 12. The power distribution method of claim 11, whereinpowering-on the second group of power outlets further includesilluminating a plurality of light-emitting-diodes associated with thesecond group of power outlets.
 13. The power distribution method ofclaim 11, wherein the method further includes programming a maximumcurrent draw value.
 14. The power distribution method of claim 11,wherein the method further includes: sensing current on the input powerline; providing the sensed current to a micro-controller; anddetermining if the sensed current is below the normal-threshold value,wherein if the sensed current is below the normal-threshold value, themethod further includes indicating a normal operation of the powerdistribution system.
 15. The power distribution method of claim 14,wherein the method further includes the steps of: determining if thesensed current is above the normal-threshold value; and determining ifthe sensed current is below the overload-threshold value, wherein if thesensed current is above the normal-threshold value and below theoverload-threshold value, the method further includes indicating a highcurrent status of the power distribution system.
 16. The powerdistribution method of claim 15, wherein the method further includes thestep of: determining if the sensed current is above theoverload-threshold value, wherein if the sensed current is above theoverload-threshold value, the method further includes indicating analarm status of the power distribution system.
 17. The powerdistribution method of claim 16, wherein if the sensed current is abovethe normal-threshold value and below the overload-threshold value, themethod further includes controlling a first group of predeterminedrelays to actuate to a non-conductive state to power-off a number ofassociated power outlets.
 18. The power distribution method of claim 17,wherein if the sensed current is above the overload-threshold value, themethod further includes controlling a second group of predeterminedrelays to actuate to a non-conductive state to power-off a number ofassociated power outlets.
 19. The power distribution method of claim 18,wherein the method further includes: controlling the plurality of relaysto actuate to a non-conductive state in accordance with a predeterminedsequence and a predetermined delay to sequentially power-off the secondgroup of power outlets which are coupled to the relays; andde-energizing the input power line defined on the power strip topower-off the first group of power outlets defined on the power strip.20. A power distribution system, comprising: a plurality of powerstrips, the power strips being mounted in an equipment rack, theequipment rack having a number of slots adapted to securely hold anumber of pieces of equipment, each power strip including: a housinghaving a first end and a second end; a plurality of power outletsmounted on an exterior surface of the housing; a power managementcircuit defined on an interior region of the housing, including: acurrent sensor circuit that is adapted to receive input power over aninput power line, the current sensor circuit being coupled to a powersupply and to the power outlets; a micro-controller coupled to the powersupply and to a relay driver, the relay driver receiving control signalsfrom the micro-controller; and a plurality of relays coupled to therelay driver and to the power outlets, wherein the relays receive acontrol signal from the relay driver to actuate the relays to aconductive state to powering-on the power outlets and the relays receiveanother control signal from the relay driver to actuate the relays to anon-conductive state to powering-off the power outlets.
 21. The powerdistribution system of claim 20, wherein the power strips mounted in theequipment rack are daisy chained together to form a scalable powerstrip.
 22. An intelligent power strip, comprising: a housing; a firstgroup of power outlets defined on the housing; a second group of poweroutlets defined on the housing; a means for controlling power to thefirst and second groups of power outlets in accordance with apredetermined sequence and a predetermined delay to sequentiallypower-on the second group of power outlets, the means for controllingincluding: a means for programming the sequence for which the secondgroup of power outlets is powered-on and powered-off; and a means forprogramming delays into the power strip, the delays being related topowering-on and powering-off the second group of power outlets; a meansfor sensing current on the input power line; a means for determining ifthe sensed current is below a normal-threshold value, wherein if thesensed current is below the normal-threshold value, the power stripenables a means for indicating a normal operation of the power strip; ameans for determining if the sensed current is above thenormal-threshold value; and a means for determining if the sensedcurrent is below an overload-threshold value, wherein if the sensedcurrent is above the normal-threshold value and below theoverload-threshold value, the power strip enables a means for indicatinga high current status of the power strip.
 23. The intelligent powerstrip of claim 22, wherein the intelligent power strip furthercomprises: a means for determining if the sensed current is above theoverload-threshold value, wherein if the sensed current is above theoverload-threshold value, the power strip enables a means for indicatingan alarm status of the power strip.
 24. The intelligent power strip ofclaim 23, wherein if the sensed current is above the normal-thresholdvalue and below the overload-threshold value, the power strip furtherenables a means for controlling a first group of predetermined relays toactuate to a non-conductive state to power-off a number of associatedpower outlets.
 25. The intelligent power strip of claim 24, wherein ifthe sensed current is above the overload-threshold value, the powerstrip further enables a means for controlling a second group ofpredetermined relays to actuate to a non-conductive state to power-off anumber of associated power outlets.
 26. The intelligent power strip ofclaim 25, wherein the power strip further includes: a means forcontrolling the plurality of relays to actuate to a non-conductive statein accordance with a predetermined sequence and a predetermined delay tosequentially power-off the second group of power outlets which arecoupled to the relays; and a means for de-energizing the input powerline defined on the power strip to power-off the first group of poweroutlets defined on the power strip.